PSYCH 1 Chapter Notes -Neuroglia, Myelin, Resting Potential
Document Summary
Advantage of action potential over simple electrical conduction is that in reaches the brain at full strength unlike electricity, which although instantaneous, would weaken as it went along. Disadvantage is that action potentials take time; ~1/20 of a second: touch perceptions, for example, are delayed while the message travels to the brain. How action potentials work: when an axon is not stimulated, its membrane has a resting potential. a. resting potential: an electrical polarization across the membrane (or covering) of an axon. Inside has a charge of ~-70mv i: gets this value from negatively-charged proteins inside the axon, mechanism called na/k pump pumps na ions out and k ions into the axon. Na ions are more concentrated outside and k ions more concentrated inside: can start in one of two ways: spontaneous activity or input from other neurons that excite the neuron"s membrane. a.
